Support rollers for centrifugal casting equipment



Dec. '3, 1966 JlRO AKIYAMA ETAL 3,290,737

SUPPORT ROLLERS FOR CENTRIFUGAL CASTING EQUIPMENT Filed May 10, 1965 United States Patent 3,290,737 SUPPORT ROLLERS FOR CENTRIFUGAL CASTING EQUIPMENT Jiro Akiyarna and Takahiko Wakita, Osaka, Japan, as-

signors to Kubota Tekko Kabushiki Kaisha, Osaka,

Japan, a corporation of Japan Filed May 10, 1965, Ser. No. 454,490 2 Claims. (Cl. 22-65) This invention relates to a centrifugal casting equipment, and particularly equipment which will cast products of carbon steel, alloy steel, and the like.

An object of our invention is to provide a centrifugal casting equipment which will not produce cracks in the finished steel .product.

In conventional centrifugal casting devices in which carbon steels or alloys are cast, it is found that cracks are formed in the finished product because the casting temperature is much higher with steel than with cast iron or copper or their alloys. Both carbon steel and steel alloys do not achieve eutectic solidification, as is the case with cast iron. After starting the solidification the steels will quickly enter a sticky stage, which includes both solid and liquid phases. Thus the shrinkage during solidification is great. This is especially so when casting pipe which has a large diameter, and also thick walls and has a considerable length.

A further object of our invention is to provide a resil ient roller support for the molding flask to substantially eliminate vibration which might be transmitted to the molding flask, and thence to the cast products within the flask.

Still another object of our invention is to provide a vibration absorbing buifer material between the drive shaft and the rollers which support the molding flask.

Other objects, advantages and features of invention may appear from the accompanying drawing, the subjoined detailed description and the appended claims.

In the drawing:

FIGURE 1 is a diagrammatic side view of our centrifugal casting equipment.

FIGURE 2 is a side elevation of one of the flask supporting rollers with parts broken away to show interior construction.

FIGURE 3 is a fragmentary sectional view taken on line 33 of FIGURE 2.

FIGURE 4 is a perspective view of one of the coupling pins.

Referring more particularly to the drawing, our mol ing flask equipment consists of a molding flask 1 of usual and well known construction, and into one end of which a trough 2 extends. The molten metal is intro duced into the flask 1 from a :ladle 3, which also is of usual and well known construction and is normally used in this art. The flask 1 is supported and rotated by means of a motor 4 and the drive shaft 5 of this motor; A plurality of wheels or rollers 6 are fixedly mounted on the shaft 5 and these rollers bear against circular rings or flanges 7 on the flask 1.

We have discovered that cracks in the steel castings will occur in the area adjacent to the flanges 7 and the driving rollers 6. These cracks are caused by vibration which takes place between the molding flask 1 and the rollers 6. To prevent the transmission of vibration from the rollers 6 to the flanges 7 on the flask 1, and thence to the steel product which is being cast within the flask, we provide a flexible or yieldable buifer material Within "ice the roller 6 to absorb the vibration before it is transmitted to the flask 1. The construction of the rollers 6 is as follows:

A hub 8 is fixedly attached to the drive shaft 5 in a suitable manner. A tire 9 is remo-vably mounted on the periphery of the hub 8 and is also provided with suitable antiv-ibration means between the tire and the hub, as will be subsequently described. The tire 9 is formed with an inwardly projecting rib 10 which fits into a suitable groove in the hub 8 and against one side of the flange 11. The flange 11 is integrally fonmed with the hub 8 and is of sufiicient thickness to provide support for the mounting means of the tire 9. A ring 12 fits on the hub 8 and is held in position by a plurality of studs or bolts 13. The ring 12 is thus positioned opposite the flange 11 and these parts provide a groove in which the rib 10 fits. A circular strip 14 is positioned between the tire 9 and the outer periphery of the ring 12 to act as a cushion or vibration absorber between these parts. A second ring 15, also formed of an elastic material, is positioned between the bottom of the tire 9 and the outer periphery of the flange 11, 5 also act as a vibration dampener and to .prevent the transmission of vibrations from the shaft 5 to the tire 9. A third ring-shaped packing 16 is provided between the lower surface of the rib 10 and the hub 8 to provide another vibration dampener and prevent the vibration of the tire 9.

To hold the tire 9 securely in a position on the hub 8, we provide a plurality of pins 17 which include a central portion 18 of larger diameter than the projecting studs 19 and 20. A ring packing 21 and 22 is closely fitted on the studs 19 and 20 respectively, and these ring packings or sleeves are formed of an elastic material and inhibit the transmission of vibration from the pins 17 to the tire 9. The ring packing 21 is held in position by a bolt 23 which screws into the outer end of the stud 19, and the sleeve 22 is similarly held in place by the bolt 24 which screws into the outer end of the stud 20.

Thus is will be evident that all of the parts of the hub 8 and the tire 9 which might be in contact with each other to transmit vibration, are separated by an elastic ring or sleeve, thus preventing the transmission of vibration to the tire 9 and thence to the flask 1 and to the steel or steel alloy casting which is being formed within the flask.

Having described our invention, we claim:

1. A centrifugal casting equipment comprising,

a flask, and a ladle to feed molten metal into the flask,

supporting rollers engaging the outer surface of the each roller including a hub and a tire surrounding the hub and mounted thereon,

a drive shaft, said hub being afl'lxed to the drive shaft,

an inwardly projecting rib on the tire, said hub having a peripheral groove therein to receive said rib, elastic nonmetallic means interposed between the hub and'the tire,

a pin extending transversely through the hub and the rib of the tire,

a resilient nonmetallic sleeve surrounding the pin at both ends thereof,

said sleeve being interposed between the pin and the hub.

2. A centrifugal casting equipment comprising,

a flask, and a ladle to feed molten metal into the flask,

supporting rollers engaging the outer surface of the each roller including a hub and a tire surrounding the hub and mounted thereon,

a drive shaft, said hub being aflixed to the drive shaft,

an inwardly projecting rib on the tire,

said hub having a peripheral groove therein to receive said rib,

a pin extending transversely through the hub and the rib of the tire,

a resilient nonmetallic sleeve surrounding the pin at both ends thereof,

said sleeve being interposed between the pin and the hub,

a pair of circular nonmetallic and elastic strips positioned one on each side of said rib and interposed bet-ween the tire and the hub,

and a third circular strip formed of nonmetallic and 4 elastic material interposed between the inner surface of said rib and the hub.

References Cited by the Examiner UNITED STATES PATENTS 403,326 5/1889 Burri-dge 295-17 722,378 3/ 1903 McGuire 29511 1,839,237 1/1932 Lord 295-11 1,840,898 1/1932 Gunn 29511 2,822,598 2/1958 Chanlllnd et a1. 253O FOREIGN PATENTS 704,775 3/ 1965 Canada.

J. SPENCER OVERHOLSER, Primary Examiner.

E. MAR, Assistant Examiner. 

1. A CENTRIFUGAL CASTING EQUIPMENT COMPRISING, A FLASK, AND A LADLE TO FEED MOLTEN METAL INTO THE FLASK, SUPPORTING ROLLERS ENGAGING THE OUTER SURFACE OF THE FLASK, EACH ROLLER INCLUDING A HUB AND A TIRE SURROUNDING THE HUB AND MOUNTED THEREON, A DRIVE SHAFT, SAID HUB BEING AFFIXED TO THE DRIVE SHAFT, AN INWARDLY PROJECTING RIB ON THE TIRE, SAID HUB HAVING A PERIPHERAL GROOVE THEREIN TO RECEIVE SAID RIB, ELASTIC NONMETALLIC MEANS INTERPOSED BETWEEN THE HUB AND THE TIRE, A PIN EXTENDING TRANSVERSELY THROUGH THE HUB AND THE RIB OF THE TIRE, A RESILIENT NONMETALLIC SLEEVE SURROUNDING THE PIN AT BOTH ENDS THEREOF, SAID SLEEVE BEING INTERPOSED BETWEEN THE PIN AND THE HUB. 